It is believed that the feeder of this application is classified in class 222/411. For relevant prior art, see U.S. Pat. Nos. 1,914,162; 1.751,335; 3,804,303; and 3,036,745. For other art of interest wherein the blade does not rotate about a fixed axis, see U.S. Pat. No. 3,809,286. It is believed that none of the feeders in said patents are truly volumetric feeders wherein a predictable amount of solids are uniformly fed per unit time. It is also believed that the vessels disposed above the feeders in said patents must be emptied prior to performing any repairs on the feeders.
The apparatus of the present invention for feeding flowable solids includes a housing adapted to be attached to a storage vessel. The housing includes a discharge port adjacent a lower end thereof. A cone is supported by the housing with the lower periphery of the cone above the elevation of said port. An annular disc is removably supported by the cone and the upper end of the housing in order to block communication into the housing.
The housing supports at least one feeder blade for feeding solids from within the housing to said port. A means is provided to support the blade for rotation in one direction about the axis of said discharge port with the blade at an elevation below the elevation of said periphery of said cone. The blade has an outer end on which is attached the curved tip portion. The curved tip portion preferably extends outwardly beyond the periphery of the cone and is curved in the direction of rotation to feed solids inwardly to the discharge port.
The blade has an upright fin secured thereto and extending from a location adjacent the tip portion to a location adjacent the discharge port. The height of the fin is greater than the thickness of the tip portion. The outermost end of the fin is coextensive with the innermost end of the tip portion to form a substantially continuous surface for moving solids inwardly to the discharge port as the blade rotates.
An annular disc is provided for sealing communication between the storage vessel and the housing whenever repairs are to be performed on the feeder. The annular disc is divided, in the preferred embodiment, into four quadrants or sections and is supported along its inner edge by the cone and along its outer circumference by the upper end of the vertical wall of the housing. With the four sections of the annular disc in place, communication between the storage vessel and the housing is completely blocked. The seal enables the entire blade structure to be removed from the housing for repair.
In addition to providing positive volumetric feeding, the apparatus of the present invention has a high feed capacity and improves the feeding of low density hard-flowing solids such as bran, rice hulls, cut plastic film, as well as aerated solids that have a tendency to flow like a liquid. The apparatus of the present invention also provides a simplified method of gaining access to the interior of the feeder in order to facilitate repairs thereto.
It is an object of the present invention to provide a novel apparatus for feeding flowable solids.
It is another object of the present invention to provide a means for blocking communication between a supply vessel and the housing of a feeder.
It is another object of the present invention to provide a method of repairing a volumetric feeder without the necessity of emptying a supply vessel prior to performing the repairs.
Other objects will appear hereinafter.